I have this light in my dorm. It is only 10 feet away from the wall, and it covers the entire wall, plus half the ceiling, half the floor, and part of the walls perpendicular to the facing wall. If it were in a room with enough space to let it open up, it would easily cover a 20' x 20' wall. Sound activated mode is amazing, following every beat. Two of these would be all the lighting you need for a party of 100. The effects are very 3D as well.